金沙江干热河谷不同土地利用类型土壤水分变化特征及对降雨响应  

Characteristics of Soil Water Change and Response to Rainfall of DifferentLand Use Types in The Dry-Hot Valley of The Jinsha River

作　　者：何苗苗 刘芝芹[1] 王克勤[1] 金奕彤 金哲浩 HE Miaomiao;LIU Zhiqin;WANG Keqin;JIN Yitong;JIN Zhehao(College of Ecology and Environment,Southwest Forestry University,Kunming Yunnan 650224,P.R.China)

机构地区：[1]西南林业大学生态与环境学院,云南昆明650224

出　　处：《西部林业科学》2024年第2期9-16,共8页Journal of West China Forestry Science

基　　金：国家级大学生创新创业训练计划项目,国家自然科学基金项目(42067005);云南省高校优势特色重点学科(生态学)建设项目;云南省一流建设学科“水土保持与荒漠化防治学”建设项目,西南林业大学博士科研启动基金项目(111429);云南省本科专业综合评价“水土保持与荒漠化防治”专业建设项目(52200805)。

摘　　要：为探究干热河谷地区土壤水分变化特征及其对降雨的响应,选取位于元谋干热河谷流域的草地、青枣林地、银合欢林地、坡耕地为研究对象,运用HOBOH21_USB土壤水分监测系统实时监测土壤含水量,同时使用TE525 mm翻斗式雨量筒测定2021年1—12月的降雨量,以探明该流域土壤水分时间变化特征和垂直变化特征及各土层土壤含水量对不同级别降雨的响应。结果显示:(1)研究区4种土地利用类型土壤水分季节变化可划分为稳定期(1—5月)、快速增长期(6—7月)、稳升期(8—9月)和消耗期(10—12月)。(2)土壤水分含量垂直变化整体随土层深度增加而增加,小部分土层与总趋势有偏差。(3)在小雨(0.1~10 mm)情况下,4个样地均只有0~20 cm土层水分含量有微弱响应;在中雨(10.1~25 mm)条件下,降雨量对各样地的0~40 cm土层含水量产生补给作用;在大雨(25.1~50 mm)条件下,降雨量对各样地补给范围扩大到60 cm土层;在暴雨(>50 mm)情况下,各个样地各个土层均对降雨量有反应。结果表明:从土壤水分时空变化以及降雨响应整体来看,在该区域坡耕地比造林地更易储存土壤水分。研究结果可为气候炎热少雨,蒸发量远远大于降雨量的元谋干热河谷地区植被重建和生态恢复工作的开展提供参考。In order to investigate the characteristics of soil moisture change and its response to rainfall in the dry and hot river valley area,grassland,Ziziphus mauritiana woodland,Leucaena leucocephala woodland and sloping cultivated land located in the dry and hot river valley watershed of Yuanmou were selected as the research objects,and the soil moisture content was monitored in real time by using the HOBOH21_USB soil moisture monitoring system and rainfall from January to December of 2021 was measured by using the TE525 mm bucket rainfall cylinder to identify the characteristics of temporal and vertical changes of soil moisture and the response of soil moisture content of each soil layer to different levels of rainfall in this basin.The results showed that:(1)The seasonal variation of soil moisture in the four land use types in the study area can be divided into stable period(January to May),rapid growth period(June to July),steady rise period(August to September)and consumption period(October to December).(2)The vertical variation of soil moisture content increased with the increase of soil depth but some soil layers deviated from the general trend.(3)In the case of light rain(0.1-10 mm),only 0-20 cm soil layer of the four kinds of plots showed a weak response.Under moderate rain(10.1-25 mm)conditions,rainfall had a replenishment effect on the moisture content of 0-40 cm soil layer in different regions.Under the condition of heavy rain(25.1-50 mm),the rainfall replenishment range of various areas expanded to 60 cm soil layer.In the case of torrential rain(>50 mm),all kinds of soil strata respond to the rainfall.The findings indicated that,from the perspective of spatial and temporal changes in soil moisture as well as rainfall response as a whole,it is easier to store soil moisture on sloping cropland than on afforested land in the region and the results can provide a theoretical basis for revegetation and ecological restoration in the Yuanmou dry-heat valley area,which has a hot climate with little rainfall and wh

关 键 词：干热河谷 土壤水分 时空变化 金沙江 

分 类 号：S152.7[农业科学—土壤学] S714.2[农业科学—农业基础科学]